A torn piece of paper with 100 stick figures drawn on it.

Across a class of high school seniors, the relatively oldest students are 11.6% more likely to enroll in college than the relatively youngest students.

That's the average difference in lifetime earnings between a college graduate and a high school graduate.

Just one factor can significantly influence the likelihood that a person enrolls in a four-year college: relative age.

Researchers call this the "relative age effect." The effect starts early, but the impacts ripple out for years.

Born on the Wrong Side of the Year

$552,500

A torn piece of paper with 100 stick figures drawn on it.

That's the average difference in lifetime earnings between a college graduate and a high school graduate.

Just one factor can significantly influence the likelihood that a person enrolls in a four-year college: relative age.

Researchers call this the "relative age effect." The effect starts early, but the impacts ripple out for years.

Across a class of high school seniors, the relatively oldest students are 11.6% more likely to enroll in college than the relatively youngest students.

Born on the Wrong Side of the Year

$552,500

In the United States, a child must turn 5 years old by September 1st in order to enroll in kindergarten that year, although the exact cutoff date can vary by school district. If they turn five after September 1st, they have to wait until the following year to start kindergarten.

For example, if your birthday is August 5th and the cutoff date for your school was September 1st, then you could have been 11 to 12 months younger than a student born in September. If you were born in the six months leading up to the cutoff date, you can consider yourself relatively younger. If you were born in the six months immediately following the cutoff date, you can consider yourself relatively older.

Relative Age

Were you relatively younger or older than your classmates when you entered school?

Younger
Older
100 stick figures lined up on a piece of paper by calender month. Blue and orange brush strokes highlighting which months are most affected by the relative age effect.

The closer a student’s birthday is to their school’s cutoff date, the more dramatic the relative age effect is.

A student with an August birthday would be 17% younger than a classmate born in September.

States and school districts do not have to adhere to a September 1st cutoff, but most still fall between August and October.

100 stick figures lined up on a piece of paper by calender month. Blue and orange brush strokes highlighting which months are most affected by the relative age effect.

A student with an August birthday would be 17% younger than a classmate born in September.

The closer a student’s birthday is to their school’s cutoff date, the more dramatic the relative age effect is.

Advanced Placement

Were you placed in any advanced classes or programs in school?

No
Yes
100 stick figures arranged under the title '4th grade.' Blue and orange stick figures divided across three torn pieces of paper, titled '4th grade,' '5th grade,' and '5th grade, gifted and talented.'

Researchers have found that the oldest students score 4-12 percentiles higher than the youngest students at the fourth grade level.

Older students who test better than their younger peers are more likely to be chosen for gifted and talented programs.

Younger students who don’t test as well as older classmates are more likely to repeat a grade while their peers move forward.

100 stick figures arranged under the title '4th grade.' Blue and orange stick figures divided across three torn pieces of paper, titled '4th grade,' '5th grade,' and '5th grade, gifted and talented.'

Researchers have found that the oldest students score 4-12 percentiles higher than the youngest students at the fourth grade level.

Older students who test better than their younger peers are not only more likely to be chosen for gifted and talented programs, they’re also less likely to repeat a grade.

Admissions Tests

Did you take any college admissions exams, such as the SAT or ACT?

No
Yes
100 stick figures inside of the bubbles on a bubble test answer sheet. Blue circles filling in all but 4 of the bubbles. 4 orange X marks eliminate the younger students who didn't take the test.

Roughly 8% fewer young students take the SAT or ACT compared to their relatively older classmates. That’s 4 in every 50 students.

The relatively youngest students are underrepresented in the “pre-university stream,” measured here as taking the SAT or ACT

100 stick figures inside of the bubbles on a bubble test answer sheet. Blue circles filling in all but 4 of the bubbles. 4 orange X marks eliminate the younger students who didn't take the test.

Roughly 8% fewer young students take the SAT or ACT compared to their relatively older classmates. That’s 4 in every 50 students.

The relatively youngest students are underrepresented in the “pre-university stream,” measured here as taking the SAT or ACT

College Enrollment

Did you enroll in a four-year college or university?

No
Yes
Blue and orange stick figures arranged under the title 'Stick Figure High, Class of '23.' A polaroid picture taped overtop the first image that includes 94 stick figures, titled 'University of Stick, Class of '27.' 6 orange figures are off on the margin.

By the time a student graduates from high school, the relative age effect has effectively stopped, but the pattern of cumulative advantage it created continues.

Relatively younger students are nearly 12% less likely to enroll in a four year college than their older classmates. That’s 6 in every 50 students.

Blue and orange stick figures arranged under the title 'Stick Figure High, Class of '23.' A polaroid picture taped overtop the first image that includes 94 stick figures, titled 'University of Stick, Class of '27.' 6 orange figures are off on the margin.

By the time a student graduates from high school, the relative age effect has effectively stopped, but the pattern of cumulative advantage it created continues.

Relatively younger students are nearly 12% less likely to enroll in a four year college than their older classmates. That’s 6 in every 50 students.